The main goal of this project is the elucidation of the immunological response induced by isolated microbial components and tumor-associated antigens that are efficacious antitumor agents. In the past year, attempts were made to: 1. evaluate fractions of Corynebacterium parvum prepared by phenol-water extraction for lymphoreticular stimulation and antitumor activity, 2. isolate, in soluble form, the component from C. parvum responsible for tumor regression, 3. evaluate inhibition of immunity and induction of suppressor cells with components isolated from microorganisms, 4. evaluate tumor-associated antigens isolated from murine tumor cells and guinea pig ascites fluid for antitumor activity, and 5. determine the cross-reactivity between tumor cells and microbial components.